Wage inequality between education groups in the United States has increased substantially since the early 1980s. The relative number of college-educated workers has also increased dramatically in the postwar period. This paper presents a unified framework where the dynamics of both skill accumulation and wage inequality arise as an equilibrium outcome driven by measured investment-specific technological change. Working through equipment-skill complementarity and endogenous skill accumulation, the model does well in capturing the steady growth in the relative quantity of skilled labor during the postwar period and the substantial rise in wage inequality after the early 1980s. Based on the calibrated model, we examine the quantitative effects of some hypothetical tax-policy reforms on skill accumulation, wage inequality, and welfare.

Consider an economy in which various types of labor are used to produce consumption, but not all types of labor are useful for upgrading the stock of organization capital–that is, for replacing old projects with more productive new projects. When news induces consumers to want to save more, low-quality projects are destroyed across all sectors of the economy, even though the economy is set to increase its stock of new projects. Labor that can be used to create new projects becomes more expensive and labor that cannot becomes cheap. Average wages may not change at all, and the employment of workers who cannot invest in new projects will decline. If physical capital complements the inputs of these workers, investment in physical capital tends to move together with their employment. These results are derived analytically for a prototype economy that has the essential ingredients of empirically relevant equilibrium models of firm heterogeneity.

Comparing U.S. GDP to the sum of measured payments to labor and imputed rental payments to capital results in a large and volatile residual or “factorless income.” We analyze three common strategies of allocating and interpreting factorless income, specifically that it arises from economic profits (Case Π), unmeasured capital (Case K), or deviations of the rental rate of capital from standard measures based on bond returns (Case R). We are skeptical of Case Π as it reveals a tight negative relationship between real interest rates and markups, leads to large fluctuations in inferred factor-augmenting technologies, and results in markups that have risen since the early 1980s but that remain lower today than in the 1960s and 1970s. Case K shows how unmeasured capital plausibly accounts for all factorless income in recent decades, but its value in the 1960s would have to be more than half of the capital stock, which we find less plausible. We view Case R as most promising as it leads to more stable factor shares and technology growth than the other cases, though we acknowledge that it requires an explanation for the pattern of deviations from common measures of the rental rate. Using a model with multiple sectors and types of capital, we show that our assessment of the drivers of changes in output, factor shares, and functional inequality depends critically on the interpretation of factorless income.

The sectoral composition of global saving changed dramatically during the last three decades. Whereas in the early 1980s most of global investment was funded by household saving, nowadays nearly two-thirds of global investment is funded by corporate saving. This shift in the sectoral composition of saving was not accompanied by changes in the sectoral composition of investment, implying an improvement in the corporate net lending position. We characterize the behavior of corporate saving using both national income accounts and firm-level data and clarify its relationship with the global decline in labor share, the accumulation of corporate cash stocks, and the greater propensity for equity buybacks. We develop a general equilibrium model with product and capital market imperfections to explore quantitatively the determination of the flow of funds across sectors. Changes including declines in the real interest rate, the price of investment, and corporate income taxes generate increases in corporate profits and shifts in the supply of sectoral saving that are of similar magnitude to those observed in the data.

Manufacturing plants have a clear life cycle: they are born small, grow substantially as they age, and eventually die. Economists have long thought that this life cycle is driven by the accumulation of plant-specific knowledge, here called organization capital. Theory suggests that where plants are in the life cycle determines the size of the payments, or dividends, plant owners receive from organization capital. These payments are compensation for the interest cost to plant owners of waiting for their plants to grow. We build a quantitative growth model of the life cycle of plants and use it, along with U.S. data, to infer the overall size of these payments. They turn out to be quite large—more than one-third the size of the payments plant owners receive from physical capital, net of new investment, and more than 40% of payments from all forms of intangible capital.

In this paper, we construct a parsimonious overlapping-generations model of human capital accumulation and study its quantitative implications for the evolution of the U.S. wage distribution from 1970 to 2000. A key feature of the model is that individuals differ in their ability to accumulate human capital, which is the main source of wage inequality in this model. We examine the response of this model to skill-biased technical change (SBTC), which is modeled as an increase in the trend growth rate of the price of human capital starting in the early 1970s. The model displays behavior that is consistent with several important trends observed in the US data, including the rise in overall wage inequality; the fall and subsequent rise in the college premium, as well as the fact that this behavior was most pronounced for younger workers; the rise in within-group inequality; the stagnation in median wage growth; and the small rise in consumption inequality despite the large rise in wage inequality. We consider different scenarios regarding how individuals’ expectations evolve during SBTC. Specifically, we study the case where individuals immediately realize the advent of SBTC (perfect foresight), and the case where they initially underestimate the future growth of the price of human capital (pessimistic priors), but learn the truth in a Bayesian fashion over time. Lack of perfect foresight appears to have little effect on the main results of the paper. Overall, the model shows promise for explaining a diverse set of wage distribution trends observed since the 1970s in a unifying human capital framework.